Manufacture of cement.



106. COMPOSITIONS,

comma OR PLASTIC. D /Z 9/ txamine n 9 1 UNITED STATES PATENT OFFICE.

JOSEPH FIBJEEIFJLAN' GODDARD, 0F HOLLOWAY, LONDON, ENGLAND.

I MANUFACTURE OF CEMENT.

1,214,910. Specification of Letters Patent Patented Feb. 6, 1917.

1T0 Drawing. Application filed May 5, 1915. Serial No. 26,008.

To all whom it may concern: ject being to lengthen the setting time Be it known that I, JOSEPH FREEMAN and this procedure is particularly necessary GODDARD, residing at Holloway, London, N., Where the clinker has been produced in ro- England, have invented certain new and usetary kilns. I have discovered that the 5 ful Improvements in the Manufacture of Waterproofing material i. e. tannin or tan- Cement; and I do hereby declare the folnic aci may advantageously e mixe or lowing to be a full, clear, and exact descripincorporated with sum or the like and tion of the invention, such as will enable added therewith to biie clinker before grind others skilled in the art to which it appering. Not only is this method of operation 10 ta-ins to make and use the same. technically more convenient but probably This invention relates to a process for the owing to the more intimate mixture obtainproduction of an improved Portland cement, able by my improved process a cement is oband which possesses the property of being tained of exceptionally good-qualities to be to a remarkable degree waterproof, when described. 15 used in the ordinary way, either with or The invention is carried out as follows without the addition of sand or.other aggre- The waterproofing material, tannic acid gate, the process also producing a cement or tannin is mixed with sun or other having certain other improved properties to suitable form f calcium or like be described. material or s owlng cement, in the pro- P A process is already known for waterportions of 1 part weigli fidf tannic acid proofing or hardening cement, mortar, or or tannin, tob' lf y of sum. concrete, wherein the cement, either with The materials may be grounieithe%fi' ,787. or without an aggregate is mixed with a or after; mi xin or any btlier amenities? "1 Q1 0 solution of tannin or tannic acid i r 1 1vgte r kiTown means or obtaining a good and unir imam/e 0 se w ere y e pores of the form mixture may be employed. Sufiicient 21 resulting mass are filled up, the mass thus Wateris then added to produce a paste, and ,-w",P.' becoming non-porous and impervious to tfie alratarers anowearo sewn-dry? It is 7' water. then ground to g ppwder, and tl'iis'powder g Now the present invention differs from consistlng of gypsiinr'or the like having 30 that above referred to in that I have distannic acid incorporated with it. is used for covered that cement having the said properadding to the cement clinker before the latties of being waterproof and hardened to a ter is ground. considerably greater degree than resulted- The amount of the treated gypsum to be from such prior invention may be produced added to the clinker will depend on the na- 35 in a simpler and more convenient manner. ture of the latter, and on the nature of the This invention therefore relates not only to cement it is desired to obtain, and particuimprovements in the quality of the product larly on the setting t ime reg uig ed, as it is but also to improvements in the process for well known that the Sontag time of Portits production. Whereas the prior process land cement may be varied within limits by 40 was for treating cement after its manufacthe addition of varying quantities of gypsum. ture, I am now able to produce the desired It will generally be found however that an effect to a greater degree by a process which addition of treated sum corresponding is adapted to be incorporated into the ordito 0.8% by weight of iEe chnk r will yield nary process of cement manufacture. an average slow setting c 45 It is well known in the Portland cement The gaindinggfjhe mixture of treated trade that gypsum or other forms of calsium gypsum andblinkerjis iisfi all y barried biit'ifi sulfate are added to the cement clinker bea'tubeinillfand care should be taken that fore the same is ground to cement, the obduring the grinding fl e t e nperature of the aft F:

materials being ground does not rise above that at whichtannic acid might tend to decompose. I have found as a result of experiment that this temperature should not exceed 300 F.

Pormment produced according to this invention is found to possess remarkable properties of w 0 l1 1 and strength, which is shown by the following which I have obtained.

W ater resisting properties.Disks made up of cement produced according to this in-' vention, and sand in the proportions of 1 of cement to 3 of sand were prepared, the disks being half an inch thick and about two and a half inches in diameter; similar disks of cement and sand were prepared with cement in all respects similar to the above, with the exception that the added gypsum had not been treated with tannin or, other similar material. Both kinds of disks were kept in moist air for 48 hours then placed in water for three weeks, and afterward kept in moist air for one week, the temperature of the water and air during the whole of this period of storage being in both cases 15 C. Both sets of disks were then submitted to the action of water under a pressure of 4 lbs. per square inch. Those made of the untreated cement were found to be wet through in 24 hours, while in those produced from my improved cement, the water was found to have penetrated through the upper surface of the disk to a maximum depth of onetwentieth of an inch after one month. Similar, but slightly better results were obtained where the disks were made up with 1 portion of cement to 2 portions of sand.

Similar results were obtained when disks made of cement manufactured according to this invention were tested for their water resisting powers at a pressure of 52-57 lbs. per square inch. These high pressure tests also showed remarkable results.

Bodies made with cement manufactured according to this invention are also found to have grea q tensile strenggh, although they may require a onei ffe riod to develo m e a or Pcrtffid cement o o','and by way of example, the following results obtained are given:-

Briquets of the usual pattern for testing cement were made up of both neat cement and cement and sand, the materials used and the quantities being in all respects similar, except that in the one case the cement used was ordinary Portland cement, while in the other a like cement was used, but the latter had previously been treated by the addition of 0.8% of treated gypsum to the bulk. The following breaking weights in pounds per square inch of net cross section were found, the figures being in such case the av- It will thus be seen that while the treated cement under experiment took lon er than the plain cement to develop it'ssti en t 1, and this was particulafly'mm'at cement bodies, the strengthfipglly gh t aiged is a-far ..-;.a-. I .fi. M

It fray suite that if the usual amount of gypsum added to the cement be lessened byf the amount of the treated gypsum the setting times would be similar.

The soundness of the cement produced according to this invention is not affected, and samples tested by Le Chateliers test showed practically no difference in expansion between ordinary Portland cement and that manufactured with the treated gypsum.

To summarize it may be said that according to this invention a Portland cement is produced which has remarkable waterproof properties, even at comparatively high pressures, and which is of great tensile strength. At the same time the method of manufacture has no detrimental effect on the soundness.

No attempt can be made here to explain I the reason for increased strength or waterproof properties.

It is not desired to limit the invention to the precise quantities or proportions of materials stated as these may be varied to suit varying kinds of materials used or required.

I claim 1. The method of making Portland cement comprising mixing the clinker with gypsum previously treated or incorporated with tannic acid and rindin the mixture to cement, for the purposes described.

2. Portland cement consisting of a mixture of ground clinker and gypsum, said gypsum having incorporated therewith a tannin water proofing agent.

3. In the manufacture of Portland cement, mixing the clinker with gypsum previously treated or incorporated with tannin and grinding the mixture to cement, for the purposes described.

4. In the manufacture of Portland cement, mixing the clinker with gypsum previously treated and incorporated with tannic acid and grinding the mixture to cement.

5. In the manufacture of Portland cement, the process consisting in preparing a 106. COMPOSlTIONS, nami comma OR PLASTIC. 9 6

clinker, treating the gypsum with a tannin water proofing agent and drying the same, and grinding the clinker with the gypsum.

6. In the manufacture of Portland cement, the process consisting of preparing a. clinker, treating the gypsum with a tannin water proofing agent and drying the same, and grinding the clinker with the gypsum, the temperature of the material being main- 10 tained below 300 degrees Fahr.

7. In the manufacture of Portland cement, the process which consists of preparing a clinker, treating the gypsum with suflicient tannin water proofing agent to cause the gypsum to set, grinding the and grinding the gypsum with the clinker.

In testimony whereof I affix my signature in presence of two witnesses.

JOSEPH FREEMAN GODDARD. Witrsesses: R

AMES UssELL, O. J. WORTH.

Copies of this patent may be obtained for live cents each, by addressing the Commissioner of Patents,

Washington, D. G."

sum, 15 

